igc: Prefer to use the pci_release_mem_regions method

Use the pci_release_mem_regions method instead of the
pci_release_selected_regions method

Signed-off-by: Sasha Neftin <sasha.neftin@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>